marc bmp manual training module 1

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BMP Training Module 1

BMPs 101 Sponsored by: MARC Presenters: Andy Sauer, P.E. (CDM) Brenda Macke, P.E. (CDM) November 14, 2008

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Agenda 8:30-9:30 Lecture 1: BMP Manual Overview

History Definitions Basic BMP Principles BMP Evaluation Process BMP Manual Future Updates

9:40-10:30 Lecture 2: BMP Level of Service, BMP Selection and BMP Value Rating Review the level of service process Discuss BMP Selection Level of service and BMP value rating examples Treatment train

10:30-11:00 Activity 11:10 – 11:50 Lecture 3: BMP Hydrology & Introduction to BMP Design

Water Quality Volume 90% Rainfall Event Methods for calculation

11:50 – 12:00 Lecture 4: Regional Initiatives

Presenter

Presentation Notes

Green to gray?

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Lecture 1 BMP Overview

History

Definitions of BMP

Basics BMP Principles

BMP Evaluation Process

BMP Manual Future Updates

Kansas City MO

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History of BMP Manual City of Lenexa 2001 Revised 2003 for MARC/APWA project Final form adopted 2004 as a APWA

technical reference Utilizes TR-55 Method

Commonly used Well documented

Updates – APWA Water Resources BMP Subcommittee (2005-2007)

Updated BMP Manual – March 2008

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History of BMP Manual Level of Service Approach Updates Started in January 2005

BMP Subcommittee of APWA March 2008 Manual Update Future Manual Updates

Treatment Train Table Redevelopment LOS Requirements Pervious Pavement Design Guidelines Vegetated Filter Strip Design Guidelines More Design Examples

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Poll Question No. 1

How many have used, or are familiar with, the current MARC BMP Manual (March 2008)? Used it for a project ______ Review it, and used it as a guide _____ Familiar with the manual but never applied it _____ Attended a training on the manual _____ Never heard of it ________

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Why we need a BMP Manual?

1972 National Pollutant Discharge System (NPDES) established Under the Clean Water Act

1990 EPA issued the Phase I Stormwater Rule Required NPDES permit for municipalities over

100,000 Municipal Separate Storm Sewer Systems (MS4s)

1999 EPA issued the Phase II Stormwater Rule Extended the NPDES to smaller communities <

100,000 (10,000 & 100,000) NPDES permits required communities to develop a

program to reduce runoff pollutants from new development and redevelopment sites

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What is a BMP or green solution?

EPA definition: BMPs can include planning, schedules of activities, prohibitions of practices, maintenance procedures, and other management approaches necessary to prevent or reduce the pollution of waters of the United States

WERF definition: BMPs attempt to mimic

drainage patterns of the natural watershed and provide some treatment to improve quality of the water discharged

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What is a BMP or green solution?

MARC manual: Stormwater

management practice used to prevent or control the discharge of pollutants and minimize runoff to waters of the U.S. BMPs may include structural or non-structural solutions, a schedule of activities, prohibition of practices, maintenance procedures, or other management practices.

Seattle’s street edge alternatives program (www.lowimpactdevelopment.org)

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Best Management Practice (BMP)

Best – State of the Practice No definitive answer Past experience, testing, research, Unique to site

Management – Responsible Parties Improve water quality, meet NPDES Phase II Jurisdictional specific Meet specific requirements of a regional

Practice – Action or Implementation Practice = defined to carry out, apply, or to

do or perform often.

Presenter

Presentation Notes

Best Management Practices (BMPs) is a familiar term we use when talking about water quality, NPDES Phase II permits, and education to the public. We all have are own understanding of the term and use it maybe more than we should and too often forget the true meaning and intent of the acronym. The action word in the acronym is PRACTICE. Practice if you go to a dictionary is defined as to carry out, apply, or to do or perform often. Therefore what should w carry out regularly (often) to improvement water quality in our region? This and other BMP manuals often focus on the actions that are BEST not the ones that should be perform regularly. Therefore this primer is a discussion on what we should do regularly to improve water quality. Other items in this manual will focus on specific structural practices that can be implement for a specific site. This section will focus on regular practices that should be consider as key part in a stormwater management program to improve water quality.

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Basic BMP Principles

Plan for stormwater management Sustainable and “be green” Provide a level of service Improve water quality

Mimic natural hydrology Increase initial abstraction Promote infiltration, retention & ET

“Treat” the stormwater runoff Natural processes Treatment trains

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Basic BMP Principles

PLAN

MIMIC

TREAT

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Non-Structural BMPs Preserving native vegetation, existing filtration

and infiltration capacity is the most cost effective and efficient method of treatment

http://cfpub.epa.gov/npdes/stormwater/menuofbmps/index.cfm

PLAN

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Minimize Development Impacts

Minimize grading

Minimize soil compaction

Minimize tree removal

Reduce impervious surfaces

Reduce road widths

Cluster buildings

Reduce building footprints

PLAN

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Preserving Natural Hydrology, Infiltration

Capacity Management/Awareness

Community education Revise planning and development codes

• Stream buffer width • Housing density • Street width

Low Impact Development (LID) Preserve existing open space, native

vegetation Pervious landscaping Disconnect impervious cover Prevent soil compaction

PLAN

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Preserving Natural Hydrology, Infiltration

Capacity

Low Impact Development Center

PLAN

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PLAN

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BMP Evaluation Process Mid-Level

PLAN

MIMIC

TREAT

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Engineered Stormwater Treatment & Infiltration

Capture runoff near the source (Lot Level) Downspouts Driveways

Infiltration Engineered sub-grades Native plants Soil Enhancements

Evapotranspiration (ET) Plant usage Can be significant

Detention/Retention

MIMIC

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Treatment and Infiltration

Structural BMPs filter and detain runoff Infiltration basins, trenches Bioretention cells Vegetated swales Raingardens

On site A combination of structures may be necessary

Topeka KS

MIMIC

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Engineered Stormwater Treatment & Infiltration

Seattle’s street edge alternatives program

(www.lowimpactdevelopment.org)

MIMIC

University of Missouri at Kansas City / CDM

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Treatment and Infiltration: Rain Gardens

Large number being installed locally

Infiltration and evapotranspiration from plants

More green than gray Minimal engineering Decentralized

10,000 Raingardens (www.rainkc.com)

MIMIC

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BMP Evaluation Process Lowest Level

Extended detention (40 hours) to increase treatment and decrease peak flows

PLAN

MIMIC

TREAT

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Detention and Treatment

Structural BMPs detain runoff Extended Detention

Basins • Wet • Dry

Extended Detention Wetlands

Infiltration basins Typically used as

larger, centralized facilities

Topeka KS

TREAT

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Example site

Streambank Biostabilization

Culvert

Grass Swale

Wet Pond

Commercial Building

Bio-Filters

Design Documents – APWA 5600 – BMP Manual – Watershed

Master Plans

TREAT

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Structural BMP Consideration

Pollutant removal efficiency Water quality volume Site suitability Tributary area Dimensions (depth, length-width ratio) Outlet Emergency spillway Maintenance easement Routine and non-routine maintenance

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Poll Question No. 2

What sector (public or private) do you represent? Government agencies (city, county, state, or federal) ____ Engineering consulting (development,

design/construction, planning) ______ Non-profit organizations ______ Private citizens _____ Others _____

What is your role? Planners _____ Design Engineers _____ Reviewer/Approval_____ Constructor _____ Regulator ______

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BMP Evaluation Process

What are the “best” BMPs? Evaluation is usually a function of:

Site location (Location, Location, Location) Receiving water standards or objectives (e.g. TMDL) Desired aesthetics

Treatment Evaluation Percent removal

• Function of water quality coming in • May not be able to meet your water quality objective

Effluent Concentration (MARC Manual) • Pollutant specific • TSS has the greatest amount of data

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BMP Evaluation General Rule

Aesthetics/Amenity

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BMP Evaluation

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BMP Evaluation Process (cont.)

Based on the best available information Can be adjusted to meet local needs BMP Evaluated on 4 Criteria

Water Quality Value • TSS • Median Expected Effluent EMC • Source: International Stormwater Best Management

Practices Database (www.bmpdatabase.org) Volume Reduction Temperature Reduction Oil/Floatables Removal

Removal Efficiency

Regional BMP Monitoring

Johnson County Stormwater Management Program University of Kansas – Ted Peltier Kansas State University

Stacy Hutchinson – Biological & Ag. Engineering Alicia Greene – MS Graduate Student Lee Skabelund - Assistant Professor College of Architecture,

Planning & Design University of Missouri at Kansas City

Deb O'Bannon – Civil Engineering

MARC – EPA Grant Ginny Moore

Regional BMP Monitoring

EPA Webcast Slide

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EPA Webcast Slide

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EPA Webcast Slide

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BMP Value Rating 4 Goals/Objectives

Reduce Volume • Infiltration • Evapotranspiration (ET)

Remove total suspended solids (TSS) • Settling

Temperature Reduction • Urban heat island

Remove oils and floatables • Screening and netting

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New Value Rating System – Based on BMP Goals

Condensed Table 5

BMP value table is based on the 4 goals of BMPs

BMP

Median Expected Effluent

EMC TSS

Water Quality Value

Volume Reduction

Temperature Reduction

Oils/Floatables Reduction

Overall Value

Vegetation N/A 5.25 2 1 1 9.25Rain Garden < 10 4 2 1 2 9.0Infiltration Practices < 10 4 2 1 2 9.0Bioretention < 10 4 1.5 1 2 8.5Pervious or Porous Pavement 10 - 20 3 1.5 1 2 7.5Extended Detention Wetland < 10 4 2 0 1 7.0Media Filtration Practices < 10 4 0 0 2 6.0Wetland Swale 10 - 20 3 1 0 1 5.0Bio-Swale 10 - 20 3 1 0 1 5.0Extended Wet Detention 10 - 20 3 2 -1 1 5.0Native Vegetation Swale 10 - 20 3 1 0 0 4.0Extended Dry Detention Basin 20 - 50 2 1 0 1 4.0Turf Grass Swale 10 - 20 3 0 0 0 3.0

Value Ratings

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BMP Goal: TSS Effluent (Water Quality Value)

Effects of suspended solids Decrease light penetration Damage fish gills Deposits downstream Impacts aquatic habitat

Particulate removal results in wide range of pollutant removal Metals, nutrients, bacteria, oils

Scored 0-4+, >100mg/L to <10mg/L

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Why use TSS as an indicator of water quality?

TSS has predominantly been used in the past monitor BMPs

TSS is relatively easy to measure TSS can be used as a surrogate to monitor

other contaminants

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BMP Goal: Volume Reduction

Replicate predevelopment flow conditions Not just reduction of peak flow but reduction of

total runoff volume Reduce velocity and therefore erosive capability Scored 0-2

BMP

Percolation/filtration

ET

Outflow Infiltration

Runoff/inflow Runoff/inflow

Underdrain

Presenter

Presentation Notes

Need Cathy to make real figure

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BMP Goal: Remove Oils and Floatables

Oils can be toxic to plants and wildlife Disrupt other treatment processes

Floatables (trash) Clog hydraulic structures Eyesore Contain pollutants

Scored 0-2

Lenexa KS Lenexa KS

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BMP Goal: Temperature Reduction

Runoff from paved surfaces can be significantly warmer than surface water and natural runoff

Increased water temperature effects: Decreased dissolved oxygen capacity Increases pollutant reaction rates Increases solubility of many pollutants

Scored -1 to 1, increased temperature to decreased temperature

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Questions?

Comments.

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Break (10 minutes)

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Lecture 2: BMP Level of Service and Value Rating

System

Topeka KS

Hancor Inc.

Kansas City MO

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BMP Selection Flowchart

Level Of Service

BMP Value Rating

Water Quality Volume/sizing

Placement Maintenance

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Level of Service

Step 1 – Determine Pre-Development Conditions

Step 2 – Determine Post-Development Conditions

Step 3 – Calculate the difference . . . . . . This is the level of service

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Level of Service

Level of Service: Rating the predevelopment condition of the site and determining what treatment system will, at a minimum maintain that condition

Step-by-step procedure in BMP manual

Kansas City MO

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Pre-Development

Insert an aerial photo of an undeveloped area

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Level of Service Previously Undeveloped

Predevelopment curve number (CN) Vs. post development CN

Area weighted CN = Σ (CNi * Areai) / Total Area

Area weighted CNpost – Area weighted CNpre

Procedure for calculating individual CN is

detailed in Table 1, p. 27 in the BMP manual

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Level of Service Previously Undeveloped

* Does not meet APWA 5600 definition of “Development”; applies only where more stringent local requirements are in effect

Change in CN Impact Level of service

17 or greater High water quality impact 8

7 to 16 Moderate water quality impact 7

4 to 6 Low water quality impact 6

1 to 3 Minimal water quality impact 5

0 Negligible 4*

-7 to -1 Minimal water quality improvement 3*

-8 to -17 Low water quality improvement 2*

-18 to -21 Moderate water quality improvement 1*

-22 or less High water quality improvement 0*

Table 2, p. 28

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Level of Service Redevelopment

% impervious surface of existing site vs. % impervious surface of proposed site

Developed sites are grouped into 4 ranges • Range #1 = <12% • Range #2 = 12-25% • Range #3 = 25-65% • Range #4 = >65%

Level of service is base on increase in range Increase in Range # = Range#(proposed) – Range#(existing)

Tables 3 and 4 in manual

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Level of Service Redevelopment

Increase in range of %imperviousness Impact

Level of Service

+3 High water quality impact 7 +2 Moderate water quality impact 6 +1 Low water quality impact 5 None Negligible water quality impact 4* -1 Low water quality benefit 3* -2 Moderate water quality benefit 2* -3 High water quality benefit 1*

* Does not meet APWA 5600 definition of “Development”; applies only where more stringent local requirements are in effect

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Future Manual Updates: Level of Service Redevelopment

APWA water resources BMP subcommittee

Evaluated current calculation Proposing a revision

Revision must be approved before becoming a part of

the manual.

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Poll Question No. 3

Who has calculated a level of service for a previously undeveloped site?

Who has calculated a level of service for a redeveloped site?

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Post Development BMP Selection

The area weighted value rating (VR) of the site must equal or exceed the level of service (LS) This includes all BMPs for a given site Can be a combination of various BMPs

Determine value ratings for each BMP using Table 5 in Section 4 of manual

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Calculate the Area weighted average of the VR

Area weighted VR = Σ (VRi * Areai ) / Total Area

Area weighted VR ≥ LS

If the VR does not satisfy the LS requirement an adjustment of the design will have to be made

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Previously Undeveloped Site Example

10 acres of undeveloped farm land

Acres Cover type Condition

6 Fallow Crop, residue

Good

3 Woods Good

1 Brush Fair

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Use the NRCS soil survey website to find the HSG http://websoilsurvey.nrcs.usda.gov

For this example: HSG for silty loam is B


http://websoilsurvey.nrcs.usda.gov/

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Using Table 1 in BMP manual to find the CN for each cover type:

Finding the area averaged CN:

CNavg = (6*83+3*55+1*48)/10 = 71

Acres Cover type Condition HSG CN 6 Fallow Crop,

residue Good B 83

3 Woods Good

B 55

1 Brush Good B 48


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10,000 Raingardens (www.rainkc.com)

Previously Undeveloped Site Example – BMP Design

Option 1 8 acres of ¼ acre lot residential

Rain gardens for each lot (32 Rain gardens) Each rain garden can capture ¼ of the lot area

Street runoff directed to 4 rain gardens 1 acre of native vegetation preserved or

established

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Development plan:

Note: Postdevelopment HSG is assumed to be one group higher then predevelopment unless a soil treatment plan is provided

Area Cover type HSG CN 8 ac 1/4-acre residential

lots

C 83

1 ac Streets NA 98 1 ac Native grass, shrubs

(informal) B (using soil preservation method in appendix A)

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Option 1

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Post Development area averaged CN: CNavg = (8 ac * 83) + (1 ac * 98) + (1 ac * 48) / 10 ac = 81

Change in CN

CNchange = 81- 71 = 10

Level of service = 7


Option 1

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BMP plan:

Area Cover type BMP Treatment Area

Value Rating

8 ac 1/4-acre residential lots

Rain Garden for each lot 32 Rain Gardens Treat ¼ of the lot

2 ac 9.0

1 ac Streets Rain Garden to capture street runoff 4 Rain Gardens

1 ac 9.0

1 ac Native grass, shrubs

Preserve or Establish Native Vegetation

1 ac 9.25


Option 1

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Option 1 Area averaged VR:

VRavg = (2 ac* 9.0) + (1 ac * 9.0) + (1 ac * 9.25) / 10 ac = 3.63

Does not meet the required level of service of 7 How many rain gardens would it take to meet level of

service? Lot rain gardens would need to treat 5.75 ac (72%) 3 rain gardens per lot

Incorporated into HOA covenant Design Maintenance


Option 1

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4 acres of 1/8 acre lot residential 2.2 acre of native vegetation preserved or

established 3 acre of wooded vegetation preserved


Option 2

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BMP Plan

Area Cover type HSG CN 4 ac 1/8-acre residential lots

C 90

2.2 ac Native grass, shrubs (informal)

B (using soil preservation method in Appendix A)

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3 ac Woods B 55 0.8 ac Street NA 98


Option 2

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Post Development area averaged CN: CNavg = (4 ac * 90) + (0.8 ac * 98) + (2.2 ac * 48) +

(3 ac * 55) / 10 ac = 71

Change in CN

CNchange = 71- 71 = 0

Level of service = 4


Option 2

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Previously Undeveloped Site Example– Option 2

BMP plan:


Value Rating

4 ac 1/8-acre residential lots

No BMPs 0 ac 0

0.8 ac Streets No BMP 0 ac 0 3.0 Woodland Preserve 3.0 ac 9.25

2.2 ac Native grass, shrubs


2.2 ac 9.25

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Option 2: Higher Density with Woodlands & Native Vegetation Area averaged VR:

VRavg = (3 ac* 9.25) + (2.2 ac * 9.25) / 10 ac = 4.8

Exceeds the required level of service of 4 Portion of site not treated by a BMP

Previously Undeveloped Site Example – Option 2

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VR Increase by Combining BMPs

Selecting multiple BMPs with complementary treatment mechanisms can increase the value rating

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Treatment train (VRTT* ATT) Wetland Swale Extended Wet Detention (0.5 ac) Table 6 for VR

Preserve 1 ac of native area


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VR = 9.5

83

7.5 acres of ¼ acre lot residential

Runoff enters wetland swale to 0.5 acre Extended Wet Detention Basin

1 acre of native vegetation preserved or established


Option 3

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Development plan:

CN = 82; 82-71 = 11 for a LS = 7 Note: Postdevelopment HSG is assumed to be one group

higher then predevelopment unless a soil treatment plan is provided

Area Cover type HSG CN 7.5 ac 1/4-acre residential

lots C 83

1 ac Streets NA 98 0.5 ac Extended wet

detention NA 98

1 ac Native grass, shrubs (informal)

B (using soil preservation method in appendix A)

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Option 3

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BMP plan:


Value Rating

7.5 ac 1/4-acre residential lots

Wetland Swale to Extended Wet Detention

7.5 ac

9.5

0.5 ac Extended wet detention

Extended Wet Detention

0.5 ac

5.0

1 ac Streets No BMP 0 ac 0 1 ac Native

grass, shrubs


1 ac 9.25

VRavg = (7.5 ac* 9.5) + (0.5 ac * 5) + (1 ac * 9.25) / 10 ac = 8.3


Option 3

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Previously Undeveloped / Redevelopment Site

Examples Detailed examples and

worksheets in BMP manual

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Woods Fair Condition HSG B Area = 3 Ac

Contoured Crops Good Condition HSG B Area = 19 Ac

Contoured Crops Good Condition HSG B Area = 8 Ac

Total Site = 30 Acres

A

B

Activity – Level of Service

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Answer Key – BMP Option 1

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Answer Key – BMP Package1/2/3

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Answer Key – BMP Package 1 B. Postdevelopment CN

Cover Description Soil HSG1CN from Table 1 Area (ac.)

Product of CN x Area

A - 1/3 Acre Lots C 81 2.10 170A - 1/4 Acre Lots C 83 4.40 365A - Streets (Curb & Gutter) NA 98 1.42 139B - 1/3 Acre Lots C 81 4.43 359B - 1/4 Acre Lots C 83 13.20 1096B - Streets (Curb & Gutter) NA 98 3.25 319Extended Wet Detention Basin NA 98 1.20 118

Totals: 30.00 2565

1 Postdevelopment CN is one HSG higher for all cover types except preserved vegetation, absent documentation showing how postdevelopment soil structure will be preserved.

Area-Weighted CN = total product/total area = 86 (Round to integer)

C. Level of Service (LS) Calculation Change in CN LS

Postdevelopment CN: 86 17+ 87 to 16 7

Predevelopment CN: 74 4 to 6 61 to 3 5

Difference: 12 0 4-7 to -1 3

LS Required (see scale at right): 7 -8 to -17 2-18 to -21 1-22 - 0

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Answer Key – BMP Package 1 WORKSHEET 2: DEVELOP MITIGATION PACKAGE(S) THAT MEET THE REQUIRED LS

Project: Green Acres - BMP Package 1 By: NAP Date: 11/15/2007Location: Kansas City Metro Checked: BRM Date: 11/12/08Sheet __ of __

1. Required LS (from Table 1 or 1A or Worksheet 1 or 1A, as appropriate): 7

Note: Various BMPs may alter CN of proposed development, and LS; recalculate both if applicable.

2. Proposed BMP Option Package No. ___

Cover/BMP DescriptionTreatment

Area

VR from Table 5

or 61Product of VR

x AreaA -1/4 Ac. Resid. - native veg. swale 4.40 4.00 17.60A - 1/3 Ac. Resid - rain gardens 2.10 9.00 18.90 A - Streets - native veg. swale 1.42 4.00 5.68B - All Resid - Extended Wet Det. Basin 17.63 5.00 88.15B - Streets - Extended Wet Det. Basin 3.25 5.00 16.25B - Extended Wet Detention Basin 1.20 5.00 6.00

Total2: 30.00 Total: 152.58Weighted VR: 5.09

1 VR calculated for final BMP only in Treatment Train. 2 Total treatment area cannot exceed 100 percent of the actual site area.

Meets required LS (Yes/No)? NO

= total product/total area

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Answer Key – BMP Package 2

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A - 1/3 Acre Lots C 81 2.15 174A - 1/4 Acre Lots C 83 4.43 368A - Streets (Curb & Gutter) NA 98 1.42 139B - 1/3 Acre Lots C 81 2.00 162B - 1/4 Acre Lots C 83 12.55 1042B - Woods - Preserved B 60 3.00 180B - Streets (Curb & Gutter) NA 98 3.25 319B - Extended Detention Wetland NA 98 1.20 118

Totals: 30.00 2501


Area-Weighted CN = total product/total area = 83 (Round to integer)

C. Level of Service (LS) Calculation Change in CN LS





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WORKSHEET 2: DEVELOP MITIGATION PACKAGE(S) THAT MEET THE REQUIRED LS

Project: Green Acres - BMP Package 2 By: NAP Date: 11/15/2007Location: Kansas City Metro Checked: BRM Date: 11/12/08Sheet __ of __





Area

VR from Table 5

or 61Product of VR

x AreaA -1/4 Ac. Resid - native veg. swale 4.43 4.00 17.72A - 1/3 Ac. Resid - rain gardens 2.15 9.00 19.35 A - Streets to native veg. swale 1.42 4.00 5.68B - All Res to native veg. swale to EDW 14.55 8.00 116.40B - Streets to native veg. swale to EDW 3.25 8.00 26.00B - EDW 1.20 7.00 8.40 B - Woods - preserved 3.00 9.25 27.75



Meets required LS (Yes/No)? YES (If No, or if additional options are being tested, proceed below.)


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A - 1/3 Acre Lots C 81 2.15 174A - 1/4 Acre Lots C 83 4.43 368A - Streets (Curb & Gutter) NA 98 1.42 139B - 1/3 Acre Lots C 81 2.00 162B - 1/4 Acre Lots C 83 12.55 1042B - Streets (Curb & Gutter) NA 98 3.25 319B - Woods - Preserved B 60 3.00 180B - EDW NA 98 1.20 118

Totals: 30.00 2501


(Round to integer)Area-Weighted CN = total product/total area = 83

C.Level of Service (LS) Calculation Change in CN LS





97

Answer Key – BMP Option 3 WORKSHEET 2: DEVELOP MITIGATION PACKAGE(S) THAT MEET THE REQUIRED LS

Project: Green Acres - BMP Package 3 By: NAP Date: 11/15/2007Location: Kansas City Metro Checked: Date:Sheet __ of __





Area

VR from Table 5

or 61Product of VR

x AreaA -1/4 Ac. Resid. - native veg swale 4.43 4.00 17.72A - 1/3 Ac. Resid - rain gardens 2.15 9.00 19.35 A - Streets to native veg. swale 1.42 4.00 5.68B - All Res to EDW 14.55 7.00 101.85B - Streets to EDW 3.25 7.00 22.75B - EDW 1.20 7.00 8.40 B - Woods - preserved 3.00 9.25 27.75



Meets required LS (Yes/No)? NO


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Break (10 minutes)

99

Lecture 3 – BMP Hydrology & Introduction to BMP

Design

100

Water Quality Volume (First Flush -> WQv)

Generally considered to be approximately the

first ½ inch of runoff

Runoff from initial rainfall contains the highest concentration of pollutants

BMPs are designed to treat this “first flush” of concentrated runoff not extreme flood events

The Water Quality Volume (WQv) includes this first flush

101

Water Quality Volume (WQv)

Water Quality Volume (WQv): The storage needed to capture and treat 90% of the average annual storm runoff volume

Water Quality storm: The storm event that produces ≤ 90% volume of all daily storms in a year

WQv

WQv = (Precip)*(Runoff coef.)*(Area)

Presenter

Presentation Notes

Add pic of wqv

102

Why Use the WQv to size BMPs?

Retain runoff long enough to get water quality benefits

Reducing erosive flows from

smaller runoff events

103

Kansas City Water Quality Storm

Young and McEnroe 2002

Purpose Revise precipitation

frequency estimates Evaluate historical

record for trends in rainfall extremes

Estimate 90% rainfall event for stormwater quality management

1.37 inches

http://kcmetro.apwa.net

104

2003 Kansas City Precip events

0 5

10 15 20 25 30 35 40 45

Daily Precipitation (in)

# of

day

s >

or=

Kansas City Water Quality Storm

Water Quality Storm = 1.37 in

Young and McEnroe

(http://kcmetro.apwa.net)

105

Water Quality Storm Data

Stormwater Manager’s Resource Center www.stormwatercenter.net Provides 90% storm for other locations

Young and McEnroe 2002

http://www.stormwatercenter.net/

106

Water Quality Volume Calculation

Two methods Short-Cut Method

• Sites < 10 acres • Only 1 predominant cover type

Small Storm Hydrology Method

• Larger or more heterogeneous drainage areas

107

WQv Calculation

Short-Cut Method

WQv = P*Rv

P = 24 hour Water Quality Storm (inches) Rv = Volumetric run coefficient =

0.05+0.009(I) I = % site Imperviousness

108

WQv Short-cut Example

Given Tributary area (ATributary) = 2.5 acres %impervious = 80%

WQv = 1.37in * [0.05 + (0.009 * 80%)] = 1.06 in

Multiply by ATributary to get volume

1.06 * 1ft/12in * 2.5 acres = 0.22 ac-ft

If only 50% impervious WQv = 0.14 ac-ft

109

WQv Calculation

Small Storm Hydrology Method

WQv = P*Weighted Rv

Weighted Rv = Σ(Rvi*Aci)/Total area (ac) Rvi = Volumetric runoff coefficient for

cover type (table) Aci = Area of cover type i (ac)

110

Rv Table

BMP MANUAL SECTION 6, TABLE 5 VOLUMETRIC COEFFICIENTS FOR URBAN RUNOFF

FOR DIRECTLY CONNECTED IMPERVIOUS AREAS

(CLAYTOR AND SCHUELER 1996)

Rainfall (inches)

Flat roofs and large unpaved

parking lots

Pitched roofs and large impervious

areas (large parking lots)

Small impervious areas and

narrow streets

Silty soils

HSG-B

Clayey soils HSG-C and D

0.75 0.82 0.97 0.66 0.11 0.20 1.00 0.84 0.97 0.70 0.11 0.21 1.25 0.86 0.98 0.74 0.13 0.22 1.37 0.87 0.98 0.75 0.14 0.23 1.50 0.88 0.99 0.77 0.15 0.24

Note: a reduction factor may be applied to the Rv values for disconnected surfaces, consult the BMP manual hydrology section

111

WQv Small Storm Example

Given: ATributary = 26 ac

Cover Type Rv Area (acres)

Flat roofs 0.87 1.6

Parking lots 0.98 8.8

Narrow streets 0.75 3.3

Silty soil 0.14 12.3

( )∑ =××+×+×+×

=××

= inPAreaTotalAcRvWQv ii 749.037.1

263.1214.03.375.08.898.06.187.0

Multiply by ATributary to get volume

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Poll Question No. 4

What types of BMPs have been constructed in this area for new development?

What types of BMPs have been constructed in this area for redevelopment?

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BMPs – Green to Gray

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Key Points: Vegetation Native Vegetation Preserved or

Established Prevent against erosion Penetration of roots

increases infiltration Removal of pollutants

and suspended solids Aesthetic value

Kansas Biologic Survey (www.kbs.ku.edu/) Miami County, KS

115

Key Points: Vegetation Native Vegetation Preserved or

Established

Prairie Blazing Star, Liatris pycnostachya Kansas City MO

116

Natural Resource Inventory (NRI)

Map showing valuable natural resource assets

Complete for Kansas City area (8 counties)

GIS data and maps

http://www.marc.org/Environment/Smart_Growth/NRI/index.htm

Presenter

Presentation Notes

MARC has developed an inventory of digital map data showing valuable natural resource assets and ecological features in the Kansas City region. This data is intended to provide a framework for environmental planning at local and regional levels.

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NRI – Jackson County

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Structural BMP Types

Rain Gardens Bioretention Cells Extended Wet Detention Basins Extended Dry Detention Basins Extended Detention Wetlands Infiltration Structures Porous Surfaces

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Rain Gardens and Rain Barrels

UMKC Raingarden Project

Topeka KS

120

Bioretention Cells at Mize Lake Lenexa, KS

121

Bioretention Swales

Neighborhood Redevelopment

Quinton Heights Topeka, Kansas

122

Extended Detention Wetland

Belle Avenue, Topeka Kansas

123

Extended Wet Detention

Topeka KS

124

Extended Dry Detention

125

Infiltration Basins

126

Porous Pavement

Concrete Promotions

I’Lan Park Leawood KS

127

Hancor Stormwater Quality Unit Installation

128

Vortcapture VC-70 Installation

129

What have other communities done?

BMPs and Green Solution

Experiences from Other Communities Across the Nation Lenexa - www.raintorecreation.org/index.html Lincoln - www.lincoln.ne.gov/city/pworks/watrshed/ Philadelphia – www.phillyriverinfo.org/ Detroit – www.rougeriver.com/ Portland – www.portlandonline.com/bes Milwaukee – www.mmsd.com/home/index.cfm Chicago - egov.cityofchicago.org/ Pittsburgh – www.ninemilerun.org

http://www.lincoln.ne.gov/city/pworks/watrshed/

http://www.lincoln.ne.gov/city/pworks/watrshed/

http://www.phillyriverinfo.org/

http://www.rougeriver.com/

http://www.portlandonline.com/bes

http://www.mmsd.com/home/index.cfm

http://egov.cityofchicago.org/

http://www.ninemilerun.org/

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BMP Maintenance

Private Property Annual inspection submittals Tied to HOA Title Restriction

Public Property Inspect after each rainfall event > 0.5 inches Annual inspections Bi-annual maintenance (replanting and

regrading) Vegetation Management Other?

131

Lecture 4 – Regional Initiatives

132

Other Resources:

MARC Website (http://www.marc.org)

http://www.marc.org/

133

Upcoming Training Sessions

Module #2 – Extended Wet Detention & Wetlands Date: December 12, 2008 Location: Helzberg Auditorium, KCPL

Module #3 – Rain Gardens & Bioretention Date: January 23, 2009 Location: Helzberg Auditorium, KCPL

Module #4 – Extended Dry Detention & Infiltration (Pervious Pavements) Date: February 20, 2008 Location: Helzberg Auditorium, KCPL

134

Questions?

Comments.

Suggestions.

marc bmp manual training module 1

Education

updated bmp manual

bmp level of service

current marc bmp manual

bmp hydrology introduction

bmp selection level

best management practice

bmp training module

marc manual